1. Field of the Invention
The invention generally relates to the measurement of power consumption, and more specifically to the association of an electricity outlet with a respective circuit breaker or association of a power consuming device with a sensor using non-intrusive and self-powered measurement of electrical current flow through the power line, such as the power line of the circuit breaker or a power consuming device.
2. Prior Art
In a typical electricity distribution system, power is provided through a main circuit breaker and a device for measurement of the power consumption of the entire electrical network connected thereto. However, typically, the main power line is then connected to a plurality of smaller circuit breakers, each feeding a smaller section of the electrical network with its specific power requirements. The smaller circuit breakers (hereafter simply “circuit breaker” or “circuit breakers”) are adjusted to the amount of maximum current that may be used by this electrical sub-network. In industrial and commercial applications, hundreds of such circuit breakers may be installed, each controlling a section of the electrical network. Even in smaller locations, such as a house, it is not unusual to find tens of circuit breakers controlling various electrical sub-networks, where each sub-network supplies current to different electrical devices. The current is supplied to one or more devices via an electricity outlet that includes but is not limited to a wall outlet, a device connected through an outlet, a device connected directly to the circuit breaker, a device activated by a switch, a light source, HVAC, pump, electrical machinery, and the like. Devices may be connected to the sub-network through electricity outlets. In some cases, wall outlets may not be connected to a power consuming device at any given time. Other devices may be connected through current switches but with no wall outlets (for example, lighting), or wired directly to the circuit breaker (for example, HVAC, pumps). For the sake of simplicity, all of the above are referred to herein as ‘electricity outlets.
It is not unusual as time passes by that the association between the circuit breaker and electricity outlet is lost. This may happen for a variety of reasons including addition or subtraction of electricity outlets and/or circuit breakers. From time to time it is desirable to check the association between a circuit breaker and an electricity outlet. However, such an effort requires at least a two-person team, one person located near the circuit breakers and the other person moving around the facility checking each electricity outlet and communicating back with the other person to ensure coordination as the task progresses. This is both an error prone and costly procedure. Typically, the person near the circuit breakers must switch the circuit breaker between its on and off positions, resulting in a disruption to all the electricity outlets associated with the circuit breaker, regardless of whether such electricity outlet is being checked or not. Alternatively, the second person turns load switches on and off and communicates such activity to the person near the circuit breakers. The first person uses standard current measurement to check the current change on each of the circuit breakers to find the circuit breaker whose current is changed, which is a long and cumbersome process.
Some other prior art solutions are provided for low current implementations in the field of electronics. However, such small signal solutions are not practical for large currents associated with an AC supply. According to one prior art method, a modulated signal is introduced over the actual wires carrying the electrical current. However, because the method is deficient as in the case of the presence of strong interference signals, the operation of such a solution is limited. Moreover, any introduction of, for example, a transformer will result in loss of such modulated signal. This method may result in frequent misdetection due to leakage of the modulated signal to adjacent wires.
In view of the deficiencies of the prior art it would be advantageous to provide a solution for circuit tracing that increases reliability and efficiency of association of a circuit breaker to an electricity outlet. It would be further advantageous if such solution reduces the costs of performing such a task. It would be further advantageous if such task can be achieved without the need to switch the circuit breaker between on and off positions.